TRF Summer Build Off - Cygnus

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EXPjawa

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OK, after much deliberation, here's my proposed entry into the summer build contest: Cygnus, the third design of my "Constellation Series" to be built.

Solar Federation Archives said:
[FONT=&amp][FONT=&amp]In the late 21st century, breakthroughs in spacecraft propulsion allowed mankind to push out into a number of star systems containing suitable exoplanets for colonization. Many of these systems allied under the Red Star of the Solar Federation, promoting equality for all sentient beings and emphasizing technical advancement. Many of the craft developed to support further exploration were part of the so-called "Constellation Series' of designs, derived from Solar Federation Constellation Specification Manual (SFCSM). [/FONT]
[/FONT]
[FONT=&amp]
Cygnus-Class:
The Cygnus-class of deep space liners were developed to be the state-of-the-art luxury cruise ships, interstellar super-yachts of the ultra-rich and the high-priests of Syrinx. It was so named for the swans that once populated Earth-that-was, due to the vague resemblance of its airframe to the bird in flight. Though only a handful of Cygnus-class ships were actually constructed in the early 2100's, they served as flagships for the Solar Federation.

Cygus-class plan form:



[/FONT]Cygnus-class vessels were produced at the primary State Lunar Shipyard facility on Luna-1. Twenty-five were slated to be built originally, but only 11 were completed prior to the Revolution of 2112. Keel was laid for an additional 4 ships, which saw various levels of completion. Typically outfitted for 20 passengers, with sleeping quarters, rec areas, a lounge and a full cafeteria. Typical crew consisted of Captain, First Officer, Pilot, Communications Officer, Engineer, plus varied housekeeping staff. Primary sublight propulsion was a Yoyodyne Nuclear Hydrothermal Reactor (NHR), which could power the ship for decades with little maintenance or loss of performance. Later ships of this class were also fitted with twin hyperdrive motivators and Cersian Navicomputers, allowing much more efficient trans-galactic travel.

[FONT=&amp]One particular ship, christened the Spirit of Rocinante was refitted (at considerable expense) by the Musk Foundation in 2110 for a manned probe into the black hole known as Cygnus X-1, in the heart of the constellation of Cygnus. “Six stars of the Northern Cross, in mourning over their sister’s loss; in a final flash of glory, nevermore to grace the night…” A volunteer crew was chosen from the scientific community. Although communication was lost when the Rocinante crossed the event horizon, there is some evidence that the mission was at least partially successful. Also see Cygnus X-1 Manned Mission (2110).

Official renderings of the Cygnus-class deep space liner:


[/FONT]
 
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neil_w

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Looks great, need more sci-fi in the contest!

I think you'll have the award for "Most Fins" locked up. :)
 

Gary Byrum

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So THIS, is where all the artsy fartsy and rockets with transitions are. You'd think, that with the mindset most of these modelers have, that transitions are kinda yucko! I've at least, heard that before.

Nice looking design Rick. I even have some on the drawing board with the likes of those forward fins that look upside down. It's a good look for sure. Can't wait to see what you do with it. SUBSCRIBED!
 

EXPjawa

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Thanks guys. Yeah, that's from Rocksim; pardon the quality. I'm still not real good with using the lighting tools, and I'm not sure if it can even do the level of decaling detail that I see guys doing in OpenRocket. I usually just get things kinda close to the colors I intend to use as just a basic idea and do the rest in my head. To me, the program's real value is in CP calcs and flight sims, though it would be nice if the rendering functions were more capable. Either way, I don't expect to start working on this till the end of the month - there's just too much to do in the interm. That should still leave me 2 months or so, right?

I think you'll have the award for "Most Fins" locked up.
BTW, I did once win a prize in a custom bike building contest for "Best Use of Fins", for a '46 Columbia with a big tail fin that had a tail light faired into it:
IMG_0578.JPG
 

neil_w

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Yeah, that's from Rocksim; pardon the quality. I'm still not real good with using the lighting tools, and I'm not sure if it can even do the level of decaling detail that I see guys doing in OpenRocket.
Although it is very nice to be able to design and preview the entire decor in OR, the inability to have pods or fins attached to pods or fins attached to fins is really getting me frustrated these days. I'd love to be able to noodle around with designs like yours.

Ah well, maybe one day they'll actually update OR.
 

Cabernut

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Looks great! Really cool.

At first glance it looks like it would fly great on an E15.
 

KenECoyote

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This design is really cool! You've even written an entire story for it! Can you post pics of the other two rockets in the series? :)
 

Daddyisabar

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Cool. Out in the garage there is an old per-war Columbia ladies bike with a skirt guard, would make a good rack to attach rockets too. Old bikes and rockets rule.
 

EXPjawa

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The bike I used is a Columbia 3-Star Deluxe, but one of the cool things is the rocket printed on the tank. Its a bit of a Frankenstein, with bits and pieces from different eras and manufacturers. I modified skirt guards from a JC Higgins bike for the project, then tried to play up on some of the aerospace styling attributes:

IMG_0588.jpgIMG_0526.JPGIMG_0538.JPGIMG_0561.jpg
 

EXPjawa

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I've restructured the design of this model. Mainly, I went from nose cone separation to mid-split. This allows me to put the parachute into the BT60 segment rather than squeeze it into the BT50 at the front. It also allows me to use a Chute Release, reserving the nose for carrying an altimeter should I choose to. I should be able to start cutting parts for this later this week.

 

Gary Byrum

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I had the same situation with the Magic Dart. I hate trying to stuff chutes in a BT 50.
 

Screaminhelo

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I was missing your entry, I always enjoy your designs. Now, I see that you got started while I was gone and it slipped down before I could see the thread.
 

Cabernut

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I'm looking forward to seeing this come together.
 

EXPjawa

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Time for an update. I started cutting parts last night, after receiving a few needed bits from eRockets. Here's what we've got so far:


'Tis a crappy photo, but this shows what I'm starting with. There are two V-2 boat tails, an Honest John nose cone, a couple of segments of BT50H, a piece of BT60, plus some BT5 pieces with required cones, centering rings, a coupler, and a balsa bulkhead. The tubes shown are all cut to length, so I just need a little sanding of balsa to start fitting pieces together. One of the boat tails needs some repair, and the thin section got damaged in storage. Some wood filler ought to do the trick once attached to the base tube. I'll still need to dig up the finstock, which is a combination of balsa and light ply, as well as the materials needed for a safe recovery.
 

jqavins

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I like it. Did you pattern those wings after a Klingon battle cruiser?
27295251820_6d9f5aa1b1_b.jpgd7-views.jpg
 
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K'Tesh

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Did someone say Klingon?

Sorry that I somehow missed this one... I'm in now... :pop:
 

EXPjawa

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I like it. Did you pattern those wings after a Klingon battle cruiser?
View attachment 296980View attachment 296981
That never occurred to me, though I see why you'd think that. I've never been a Star Trek fanboy, so I would've never had made that connection myself. They're actually patterned after a (highly stylized) swan in flight, as is the entire shape of the ship:

 

jqavins

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Swan, yes, as the name implies. I wonder if Trek's creators had swans in mind too. The swan's long neck and the head can be seen in the Klingon design as well.
 

EXPjawa

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Time for a long-overdue update. Time is getting tight, but I think I can still manage a test flight by the end of the month. Anyway, I built up the motor mount:


This uses a BT60-sized V2 boat tail from BMS. Obviously, the motor tube is extended long enough to get a straight alignment using centering rings rather than rely on the bore in the cone. A recovery harness leader was made up from kevlar line, and the motor block was installed. No retaining hook is used, this will require friction fitting.

A second V2 boat tail is used for the transition from the "neck" body tube to the aft "body" body tube. I didn't want to rely on the bore in the cone here either, as frankly, neither were all that accurate. So I made a shoulder extension using a coupler and centering rings. The standard coupler would take up too much space, so I trimmed a little off:


And the sanded the rings to fit:


Upon gluing, this was then installed on the forward tube, together with the boat tail:


To fill the hole in the end, and give me something to attach the shock cord too, I used a BT50 balsa bulkhead. To be fair, I used part of one - I cut a piece off with a razor saw to use as a bulkhead for the payload bay at the front end:


The shorter piece becomes the payload bulkhead, the longer is the lower bulkhead, which will be drilled for a dowel later.


And we can now put the top and bottom together for a test fit, while Cap't Blondbeard looks on from the TV:


At this point, it was a good time to mark out the tubes for fin alignment. The lower body tube gets a bit complex, with 2 wings, 6 fins and 6 strakes:


Slots were cut for the wings, and the forward body tube, and tubes for the pods were also marked out. I used printouts from payloadbay.com for guides. Speaking pods, these are the parts for the wing tip pods marked and test fitted:


Keen observers will note that I elected to replace the elliptical aft-end cones with ramjet style cones. I thought it would be a more interesting styling element. And the last detail for now was that the fins were cut out, using 3/32 basswood. These are fitted to the ogive shape of the boat tail, so I had to freehand cut the root edge and trim each once for a reasonable fit. I'll have to do the same for the strakes to go on there as well. Six fins blocked together for sanding:


Next up - mark out the wings and the 22 strakes needed. The latter with be from balsa, fairly easy to cut. But the wings will be from 1/8" ply due to their complex shape. I'll probably need the scroll saw to make that easier...
 

EXPjawa

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Minor update: I've cut out and shaped the 6 modified strakes that go on the boat tail section. I say "modified", because my standard strake is taller that the front than the rear in profile. These would have the same profile in relation to a parallel body tube, but need to extend farther inward at the aft end to meet the boat tail. I'm not real happy with the sheet of balsa I cut them from; I may switch to 1/16" basswood for the 16 standard ones I have yet to make.

WP_20160817_22_39_36_Rich.jpg
 

Cabernut

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Yes! Going to see this one come together as well. One of those times you wish you had a laser cutter of your own.
 

EXPjawa

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Don't I know it. I'm waiting for that Laser Forge to actually become production, and then the cost come down, then somehow having extra $$$ for one. I can envision a time when my shop has a laser cutter, a 3D printer, a drill press and a small lathe. Then the options for scratch building really open up... :cool:
 

EXPjawa

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Alright, I'm playing catch-up with this update. When we last left off, I was cutting out the strake fins. I cut the first 6 from 3/32" balsa for the fin can. After that, however, I switched to 1/16" basswood; I didn't like how the balsa I had cut, it was too soft for my taste. I then moved on to finishing the sanding of the rear fins, then set about marking out the remaining strakes and the wings (on 1/8" ply).




The wings were cut out on the scroll saw, which I finally figured out how to tension the blade properly on, and the strakes were cut by hand with a hobby knife and straight edge. There are 12 shown marked out above, but I actually needed 4 more past that. Total number of strakes for this project: 6 (fin can) + 6 (forward body) + 10 (pods) = 22. That was a bit of a PITA, it might limit excessive use of them in future designs. Anyway, here are the fins all cut out:



With the wings cut out and the tube slotted, I did a quick test fit:



Now it starts to look like something. Anyway, the fit was pretty good off the bat. Only a little further trimming with be required.

At this point, the wings, main fins, and some of the strakes have been sanded. With the latter, I elected to sand them as I needed them. What I needed first were the ones for the fin can. I thought I'd taken more step by step photos here, but apparently did not. I glued the strakes on by putting a thin bead of Tightbond II on the root, aligning it with the marks, and putting a drop or three of CA on the leading edge to tack it in place. Then I held the tail end down and tacked that too. This worked pretty well, and I only glued my fingers to the model twice... Anyway, due the nature of these little fins, I had to align and place them by eye - the fin jigs were of no help here. It came out pretty well, though not perfect, so we'll see how straight it flies. I then repeated the basic procedure for the 6 main fins, again, with alignment done by eye only. The result:



So, while the glue dries on that, I'm moving back to the pods. I previously glued the cones to the tubes, though the fit for the long cones was less than ideal; their base diameter was visibly smaller than the tube. I wonder if eRockets picked the wrong version of the cone (Centuri size vs. Estes), because once I put glue on them, they actually slipped pretty easily over the lip of the shoulder and went into the tube too far. So, I had to muck about with that get them aligned correctly. I now have to do a little filling at the cone/tube joint to blend over the diameter difference:


The same basic thing was required between the front boat tail transition and the forward body. I may have to revisit this part and add more filler:



It appears that the core isn't bored perfectly straight, as there's a thicker lip edge on one side versus the other. You can sort of see it in the picture, as there's more filler on one side. I'll try to sand that back in line.

Anyway, there's more to the story that I'll post later. In the meantime, I need to get ready for a meeting... :blush:
 

EXPjawa

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Will do! In fact, here's more:

The next phase was attaching the strake fins to the forward body. This was considerably easier than the attaching the previous ones to the ogive boat tail. I was, for the most part, able to put a glue bead on the root, align them on the marks on the tube and press them into place. I still tacked on end with CA to be sure.



After that came straking (I just made that word up) the pods:

Boom


Boom


Boom!


Which lead to attaching said pods to the wing tips. Here, I simply aligned the tip to the mark on the pod, as if it was another fin. A bead of TiteBond II and hold in place. Tack with CA. They were then propped up using a convenient box that held them upright:



With all of that done, the obvious penultimate step is to attach the wings to the body. The slotting was accurate enough that all I had to do was sue the Estes alignment tool to make sure they stayed normal to the tube:


Once the first wing was on, I needed to prop it up somehow to allow attachment of the other. While my fin gillotine jig wouldn't work the way it was intended to for this specific rocket, due to the wack fins, it made a good support. I'm not sure what else I could've used, save maybe the vice:



and here we are, with the major parts all attached and glue drying. Or, at least that's where I left it last night...
 

EXPjawa

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Basic construction is finished. It now requires the usual glue fillets, sanding, priming, etc, not to mention a recovery system. Still, I'm planning getting flyable by this weekend, since the upcoming URRG launch is my last window to get it in the air prior to the end of the design contest. I can paint it the following week if need be...



 

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